The Design and Characterization of a Prototype Wide-Size Range Aerodynamic Focusing Lens
Loading...
Authors
Bair, Salix
Issue Date
2025
Type
Thesis
Language
en_US
Keywords
Alternative Title
Abstract
Aerodynamic focusing lenses (AFLs) are used to generate highly collimated particle beams by passing particle-laden air through a series of axisymmetric contractions. The most common use for AFLs is as inlets to aerosol mass spectrometers, which allow for the in-situ and real time analysis of aerosols to understand their physical and chemical properties. However, available AFLs focus only a small fraction of particle sizes that affect human and environmental health. Currently, multiple lens systems are needed to study the entire aerosol size range of interest, which is both cost and time prohibitive. We address this challenge by designing a prototype wide-size range AFL (P-WAFL) that attempts to focus 10 nm – 10 μm particles. Computational fluid dynamic (CFD) simulations were conducted to optimize the design, and the performance of this new AFL has been characterized both in our laboratory and at the Pacific Northwest National Laboratory (PNNL). It was found that the P-WAFL had an effective focusing range of 30 nm – 700 nm. While the P-WAFL fails to successfully focus more than one order of magnitude of particle sizes, its effective focusing range is nearly double that of the standard AFL (40–400 nm) used in the miniSPLAT instrument at Pacific Northwest National Laboratory (Zelenyuk et al., 2015). Overall, the work presented in this thesis provides a foundation for the future development of AFL systems with enhanced particle transmission efficiency over a broader range of particle sizes.